Abstract: Objectives: To investigate the toxic insult of chronic fumonisin lb (FBI) exposure on rats' lung using
light (LM) and electron microscopic (EM) examination Materials and Methods: The study comprised 60 normal
healthy growing male albino rats divided into Control group (n=15) and four study groups. Two ratios of added
Fusmium culture material were used: 10 mg/kg b.wt of feed for Study group I and 30 mg/kg b.wt of feed as a study
heavy dose for Study groups II-IV. Mean animal weight was determined weekly and percentage of weight gain in
relation to baseline weight was calculate& Five rates were randomly selected from each group to be sacrificed at 1,4
and 8 weeks after start of study regimen. At necropsy, the wet lung weight was determined and lung/body weight
ratio was calculated. The lungs were also evaluated grossly for evidence of pulmonary edema and specimens were
examined using LM and EM. Results: Percentage of body weight gain in study groups DI and IV showed
significantly lower percentage of weight gain compared both to control group and to study groups I and II with
significantly decreased weight gain in group IV compared to group III. Mean lung wet-weight to body weight ratio
was significantly increased in study groups In and IV compared to control and study groups I and IL LM
examination of lung specimens obtained from study groups showed a progressive dose and time-dependent affection
of the lung in the form of mild pulmonary congestion and alveolar edema, focal areas of interstitial edema,
pulmonary congestion with inflammatory cellular infiltration at 1-week. Specimens taken 4w alter starting the
study, showed moderate interstitial edema, scattered areas of hemorrhage, proliferation of alveolar cells and
thickening of the capillary wall. At 8 weeks lung specimens showed proliferation of alveolar lining cells with
inflammatory cellular infiltration, alveolar septal edema and scattered areas of compensatory emphysema. Two
specimens obtained from animals received high dose for 8 weeks showed scattered areas of atypia suggestive of
starting malignant transformation giving a picture of well differentiated carcinoma. EM examination of specimens
taken after 4-weeks showed thickening of the interalveolar septa and hemorrhage and interstitial fibrosis and
increased collagen fiber deposition and after 8-weeks EM examination revealed endothelial cell damage and
distortion of alveolar epithelium and showed increased alveolar macrophages with apoptotic changes in the form of
nuclear fragmentation Conclusion: Exposure to fumonisins induced variable gross and microscopic effects on lung
tissue and severity and character of these pathological changes showed dose and time dependency.
[Garnet Abdel Salam, Esam Mehlab and Mohamed El-Shishtaxy. Fumonisin Lung Toxicity: Gross and
Microscopic Changes are Dose and Time Dependent |
